<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		
		<link rel="stylesheet" href="css/index.css">
	</head>
	
	<!-- 元素选择器  -->
	<body>
		
		
		<h1>H1 </h1>
		<h2>H2 </h2>
		<h3>H3</h3>


	<p>
	hello world	
	</p>
	</body>
</html>
